It is common in the projection industry to combine multiple overlapping displays from different projectors to produce arbitrarily large and irregularly shaped displays. Such displays are typically used in immersive environments and large venues such as amphitheaters and shopping malls. The process of aligning and matching the projectors is a difficult and time-consuming task, which is typically performed by an experienced installer. If the aligning and matching process is not done properly, an unsatisfactory image such as FIG. 1a may be the result. Each projector image must align exactly to the pixel with its neighbors in order to produce an acceptable image such as FIG. 1b. In the overlapping region, where more than one projector is projecting, the brightness levels of each projector must be controlled to achieve a continuous image. Also, the colors of each projector should closely match in order to maintain the illusion of one continuous image.
U.S. Pat. No. 6,456,339 to Surati et al. and U.S. Pat. No. 6,222,593 to Higurashi et al. disclose the use of cameras and image processing to simplify the aligning and matching process of the projectors. In general, these methods involve using information regarding the display from a camera to program a “smart” image generator. The “smart” image generator provides modified images with altered geometry, color and brightness that are fed to a projector to produce a seamless geometrically correct image. The “smart” image generator, however, is limited to the capabilities of the calibration system rather than the capabilities of the projector. By requiring all of the content to pass through the “smart” image generator, latency may be introduced and the available content may be restricted. As such, a lower resolution display may result due to the maximum resolution of the calibration system being lower than that of the original image.